Safety device



May 1 1, 1948. E. OLSON ET A1. '2,441,369

SAFETY DEvIcE A l Filed oct'. le, 1944 A the roller 22 in engagementPatented May 11, V1948 derlei?.I f

. SAFETY DEvIcE Elmer` lson', Ferndale, and Stanley M7.' Udale,-

Detroit, Milch.. assignors. te George M. Holley and Earl. HillierApplication @tiene 16, 1944. serial No. 558.918

The object of this invention is to protect a marine engine fromexcessive-speed. When a. boat is traveling fast'in a rough sea, roughenough to raise the propeller out of' the vvater, theengine which drivesthe boathas. a; tendency= to g' race, and excessiveen-erl-e speeds.v areattained. The specinc object of this invention is to temporarily closethe throttlerandto simultaneously interrupt the fuel ow. I

Figure 1 shows the Vention. f

Figure 2 shows a simpler alternative construction.

Figure 3 shows a cross-sectional elevation through plane I33 of-Fig-ure'l.

Description-Figure 1 In the gure, I is the air entrance, 29 is the `fuelnozzle, 30-3I are the discharge outlets for the fuel nozzle between thethrottles I3 and 4. The air-fuel mixture is compressed in an enginedriven supercharger contained in housing 10. 68 is the fuel chambercontrolled by the diaphrams 24 and 25. The fuel inlet ||0 admits fuelpast the fuel needles and I I2 into the chamber 68. These fuel needlevalves and II2 are connected to the diaphragm 25-24 in a. well-knownmanner. The pressure on the diaphragm is controlled by the air chambers26 and 21, which are connected by the air passage 8|. 'I'he chamber 86is vented to the atmosphere through the opening 9|. The fuel outlet IIis provided with a restriction 28, which is controlled by a needle valveI2, which in its turn is controlled by a le- Ver 2|, the movement ofwhich is controlled by a roller 22 riding on a cam I9. A spring 20 keepswith the cam I9.

'I'he throttles I3 and I4 are Icontrolled by in termeshing gears I6 andI1 and a gear I5, the axis of which carries the cam I9 and is operatedby lever 92. The lever 92 is connected to a piston 93, which slides in acylinder 94, in whi-ch is a spring 95; cylinder 94 carries a stop 96 tolimit the outward movement of piston 93. A manually-operated throttlelever |09 is connected to the left-hand end of the rod |08, whichprojects from the cylinder 94. The pressure inside the cylinder 94 isthe pressure inside the chambers 26 and 21 because a flexible rubbertube 91 connects the inside of the cylinder 94 with the chambers 26 and21. A passage 98 connects chambers 26 and 21 and the cylinder 94 with achamber 99, which ycommunicates through, an opening I 00 with the throatof the variable venturi formed by throttles I3 and I4. An armaturepreferred form oi" inf 2v Y |04V carrying a valve' |02 which isattracted by an electric solenoid. 0.3 whenever the dif.- ferentialswitch 86lv admits the current from a battery 8-1 through a conductor|04. The valve |02 is arranged to'control passage 98. v A centrifugalgovernor lthrough a lever l0 operates the differential switch 86,- thegovernor being driven from the engine by the shaft, 84. The differentialswitch is adjusted to complete the circuit at 2800 revolutions perminute and to open the circuit at 2500 revolutions perminute. Figure i3`shows how the differential switch S'I'operates.

- Operation- Figure 1 When the speed exceeds a predeterminedsneed, suchas 2800 revolutions per minute, the governor 85 operates thedifferential switch 86 energizing the solenoid I 03 which raises thearmature 0| and thus the valve |02 and to admit the suction effect inthe chamber 99 into the chambers 26-21 and into the inside of thecylinder 94. The throttles |.3-I4 are thus closed at the same time thesuction in the chambers 26-21 prevents the fuel flowing along thepassage When the speed falls to 2500 revolutions per minute, thediierential switch 86 is opened, the armature |0| being released by thesolenoid |03 and the suction in the chambers 26 and 21 is destroyed.'I'he suction in the cylinder 91 is also destroyed so that the spring 95reopens the throttles and the atmospheric air pressure admitted pastopening 9| into the chambers 26 and 21 restores the normal flow of fuel.

Description- Figure 2 Operation-Figure 2 The valve |02', when open,admits suction: from the passage 98 to the flexible pipe 91 whenk thesupercharger pressure exceeds the pressure corresponding to the spring13. When the supercharger pressure 10 exceeds the value corresponding tothe compression spring 13, the valve |02 rises and the application ofsuctionto the cylinder 8'4 causes the throttle lever 92 to moveclockwise, closing the throttles I3 and i4. At the same time, suctionapplied to the chambers 26 and 21 causes the diaphragms 2d and 25 toshut olrl the supply of fuel. Meanwhile the suction in the chambers 2'6and 21 is transmitted through the passage 11 to the chamber 14 where itassists the compression pressure in cylinder 12 in compressing thespring 13. Hence, the valve |02' remains open until the revolutions perminute of the engine has fallen to the desired numf ber of revolutionsper minute, but before the enair inlet passage gine stalls. Thecompression from the' super-` charger then descend and the engine isrestarted.

Without the passage 11, the valve |02 would hunt. The engine should runslowly long enough to permit the operator to close the throttle if thevpropeller had been lost. If the propeller had merely raced due to itbeing raised free of the Water by a wave, then it would automaticallypick up speed without any attention from the operator.'v The pipe 98 isconnected to the throat of the venturi ll3-30 through the opening |00,therefore, no pressure above atmospheric presure can ever exist in thepipe 98.

What we claim is:

l. A safety device `for an internal combustion engine having an enginedriven supercharger, an air inlet passage leading thereto, a throttlevalve therein, an engine suction pipe connected to said inlet passage onthe engine side of said throttle, a control valve in said suction pipe,means responsive to the supercharger pressure for opening said controlValve when the supercharger pressure exceeds a predetermined value,means.

responsive to the engine suction thus controlled falls permitting theValve |02" to 4 for holding said valve open and for shutting off thefuel supply until the supercharger pressure falls a predetermined numberof pounds per square inch.

2. A. safety device for an internal combustion engine having an enginedriven supercharger, an leading thereto, a throttle valve therein, anengine suction pipe connected to said inlet passage on the engine sideof said throttle, a control valve in said suction pipe, means responsiveto the supercharger pressure i or opening said control Valve when thesupercharger pressure exceeds a predetermined value, means responsive totheV engine suction thus controlled for maintaining the valve in theopen position and for holding the throttle closed until thesupercharger-pressure has fallen a predetermined number of pounds persquare inch below the pressure at which said control valve opens.

ELMER OLSON. STANLEY M. UDALE.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS England. Dec. 6, 1935

